New Energetic Particle Observations at Geosynchronous by the GOES-R Series Space Environment In‐Situ Suite (SEISS)

The NASA Applications Technology Satellite (ATS) series, launched in the late 1960s, provided the first opportunities to make in-situ energetic particle measurements at geosynchronous altitude. The ATS spacecraft were followed by a series of satellites leading up to the current Geostationary Operational Environmental Satellite system (GOES) operated by NOAA. The GOES system supports weather forecasting and is used for land, atmosphere, ocean and climate research. The GOES system also monitors the near-earth space environment. The first of the new GOES-R series spacecraft (GOES-R -S, -T, -U) is scheduled for launch on 4 Nov 2016. GOES-R series instrumentation includes the new Space Environment In‐Situ Suite (SEISS), which is composed of five magnetospheric particle sensor units: an electrostatic analyzer for measuring low energy ions and electrons in 12 angular zones (MPS-Lo), a high energy particle sensor that includes fans of five electron and five proton telescopes (MPS-Hi), two Solar and Galactic Proton Sensor (SGPS) units (east and west facing), and an Energetic Heavy Ion Sensor (EHIS). Collectively the SEISS sensors measure magnetospheric electrons with energies from 30 eV to 4 MeV in 26 differential energy channels, protons from 30 eV to >500MeV in 40 channels, and 30 species of heavy ions (He-Ni) in five energy bands in the 10-200 MeV/nuc range. Measurement of 30 eV to 30 keV particles by MPS-Lo and heavy ions by EHIS are new capabilities not previously flown on the GOES system. Observations at geosynchronous support space weather monitoring by the Space Weather Prediction Center (SWPC) and also play an important role in the study of energetic particle populations in the magnetosphere. SEISS is ideally stationed for making in-situ observations of the source populations for the ring current and outer electron belts, and for studying the penetration of solar energetic particles into the Earth’s magnetosphere. This presentation will include an overview of SEISS and the energetic particle environment at geosynchronous.